Ford Focus Smart Charge Problem

Fat_Boy

Hi,

I have an 05 Ford Focus Sport (1.6) that has recently been displaying the battery warning light on the dashboard. The problem has been intermittent for the last couple of weeks but I got some mechanics at work to check it out. They confirmed that the battery and alternator were charging at 14 Amps.

Yesterday whilst driving up the A1 the light was almost constant so I called out the RAC. They confirmed the battery/alternator were charging under load at 14 Amps but after some more tests the RAC man confirmed it was a problem with my Smart Charge. I've booked the car in with the local Ford garage for next Thursday - the earliest I an do it - but as I have no idea what the Smart Charge is or does can anyone put my mind at rest about whether the car will last until Thursday (will be doing about 25 miles/day Mon - Thurs) and how much this is likely to cost to put right?

Cheers!

Antispam

I copied this from a web site I would have posted the link but my browser gave me a warning of security on that web site

This the link http://www.petercoopercarrepairs.co.uk/ford_focus_alternator_smart_charging.htm

Ford Focus alternator smart charging

First things first, check the battery, not just condition, but correct type. A lead acid battery will not work properly with smart charge, it must be Silver Calcium! Easy to over look.

Next, put a meter across the battery. Remember when you remove the smart charge 3 pin plug from the back of the alternator, it reverts to a conventional alternator! If you do not have about 13.8 volts, carry out basic charging system checks and suspect the alternator, its not a smart charge fault !

Correct charge voltage from the alternator, then its time to start on the smart charge system, and you will need a scope. First the system.

Pin 1 = Alternator Feedback
Pin 2 = Alternator Load Request
Pin 3 = Reference Voltage

Now, pin3, must MATCH battery voltage ! Its fed from a fuse in the CJB, and a high resistance on the fuse contacts causes a volt drop, and the smart charge drops out !

Next pin 1 & 2 need checking back to the PCM for resistance, isolation from ground and each other. If ok, its out with the scope.

Pin 2 is the request from the PCM to the alternator. This will be a square wave pattern that will change with load request. So lights, screens etc on and monitor for a change in the pattern. (Obviously back probing with the plug connected)
No change in the pattern means no request from the PCM, you should now suspect a PCM fault. Correct pattern and move on.

Pin 1 is the feedback from the alternator and MUST remain a constant square wave pattern. If this pattern mirrors the one on pin 2, the smart charge part of the alternator is faulty, and a new unit is required.

With these simple checks, you should always be able to diagnose a smart charge fault.

Another point to add is, never, ever, jump start a Smart Charge vehicle with a flat battery.

The system can produce up to 18 volts, which can fry major modules.

The theory behind smart charge, is a battery will take a charges at its most efficient when it’s cold. Following start up, the PCM checks the Engine coolant temp, and intake air temp, and calculates a cold engine. It will then boost the battery charge, pulling it back as it calculates the under bonnet temp coming up. Its not there to compensate high demand as is the common misconception.

The problem comes on a jump start, when the PCM sees a cold engine, and then a poor battery condition, and can then instantly zap out about 18 volts because its trying to recover the battery. Unfortunately this sudden surge can cook modules.

Fat_Boy

Thanks for that antispam, the RAC man did the first bit and confirmed the correct voltage, I guess he didn't have the equipment to undertake the other checks mentioned - though he did change/unplug 1 or 2 fuses which is apparently how he came to the conclusion that it was the Smart Charge system.

That's an interesting point to note on not jump starting the car if the battery was dead, I'd have never have known that!!!

kolin_2

Thanks for this link, i'm having a bit of an issue with my ford focus (03 TDdi), and it's battery/alternator/starter.

Occasionally the car refuses to start. a single click when i turn the ignition, and nothing. It just seems to be happening at random.
New starter motor and Battery have been purchased (2 months ago), and when it was still doing it, a new alternator. It has done it only once since the alternator was changed, but it can be really annoying. (for example I was down in dorset a couple of weeks ago and it happened, thought i was going to be stuck there!)

but as to the original problem, I was driving back home (Leeds) from scarborough, and halfway down the M62, the battery light came on. At this point i decided it would be a good idea not to stall....

harveybobbles

The 05 model Focus suffered problems with the alternator not fully charging. Ford seemed to get this problem sorted by mid 2006 models.

Midi

Hi
Since I now have exactly the same problem as Fat Boy on my 05 Ford Focus I would be interested to know what the outcome was when it was taken to the dealer.
Was it the Smart charge system or the alternator as harveyhobbles suggests?
I found a test procedure on the bba-reman.com forum but it involves disconnecting the 3 pin plug that carries the smart charge signals and I cannot pull it out. There is so little space around it that I cannot really see if there is a latch to release somewhere on the connector.
Any advice would be very much appreciated.

ukjoel

Try and get it to the dealer with the light on and the problem ongoing.

There biggest nightmare is when a car breaks down, customer calls RAC who get it running again or try a repair and then they cant find the fault when its brought in.

The computer is supposed to hold onto fault codes for specific number of ignition sequences but doesnt always do so.

Only other thing I can suggest is to buy a protable battery starter.

They dont cost much and will give you peace of mind until its fixed.

Midi

Thanks ukjoel and I would normally follow your advice but this one worries me. I have found other reports of this problem scattered around the net and am far from convinced that most auto engineers and dealers know how to fix it.

The usual response appears to be to fit a new alternator and "hope it goes away". I checked charging voltages in the normal ways and there appeared to be nothing unusual with alternator or battery. That was before I knew anything about this fancy Smart charge system that Ford have dreamed up for the Focus and that the charging indicator was driven by a bit of software, and not from the direct connection between battery and alternator auxiliary output.

I have read about the issue of one or more of the Smart charge connections breaking or corroding on the diesel Focus (mine is petrol), but I cannot check that without removing the connector from the alternator. Hence the request for help about how to get it undone.

Midi

Just a report on what happened to my 55 reg Focus. I talked to a Ford agent who had experienced the fault on several Ford Ka but not on a Focus. The solution on the Ka had been to change the alternator but there was no guarantee that it would solve the problem on my Focus.
After ignoring the warning light for about 6 months the fault suddenly developed into charge warning light coming on then speedometer reading dropping to zero. To make the speedo read again it was necessary to stop the engine then restart it again. That same night while driving down a motorway it developed to warning light, followed by speedo dropping to zero, followed by both headlights going out simultaneously. Not a nice experience. The RAC man I called out found that both headlight bulbs had blown. He replaced them and I got home safely.
I arranged for the alternator to be changed straight away. It took several days to get a new one. There appear to be dozens of different models. It has been OK now for some 9 months. No warning lights or other symptoms.
I don't think I had better say what I think of this particular bit of Ford engineering.

s_b

its usually the smart charge plug that goes into the alternator take it out clean bright it and replace,if particularly bad then you can buy the plug and part of the wiring loom from ford

reeac

A bit of a quibble but you probably mean 14 volts not 14 amps. Charging at 14 volts is pretty standard if the battery is reasonably but not fully charged. If the headlamp brightness is independant of engine speed then you're probably getting charging at idling speed as you should. i.e. probably won't break down but still needs sorting.